BOGOTA, Colombia, Aug. 20, 2013 /PRNewswire/ -- Ecopetrol S.A. (BVC: ECOPETROL; NYSE: EC; TSX: ECP) announces that it has proven the presence of hydrocarbons in the Guainiz-1 exploratory well located in the Municipality of San Carlos de Guaroa, Meta Province, Colombia. (Logo: http://photos.prnewswire.com/prnh/20090209/ARM001LOGO ) Initial tests yielded a daily average production of 409 barrels per day of 14.4° API crude and a water cut of 8.4%, through an artificial lift system of progressive cavity pump. This is the third discovery made by Ecopetrol in the CPO-10 block, after the Pastinaca and Cusuco discoveries announced in March and May 2013 respectively. The three discoveries are under the CPO-10 Exploration and Production Contract signed by Ecopetrol and the National Hydrocarbons Agency on December 18, 2008. Drilling began on the Guainiz-1 well last June and culminated on July 14 at a depth of 7,975 feet (just over 2.4 km) in Paleozoic rock. Initial tests were made on the intermediate deposit of late Eocene Age basal sandstone beds at a perforated interval of 16 feet. Positive results besides those of the tests were also obtained from fluid samples in the top of the sand packages from the Late Cretaceous period. Ecopetrol will analyze the results obtained over the next months and drill new delimitation wells in the CPO-10 block in order to enable the start of production of the future fields. In this year to date, the company has made four discoveries in the 5 exploratory Wells drilled, obtaining a success rate of 80%. Ecopetrol is Colombia's largest integrated oil & gas company, where it accounts for 60% of total production. It is one of the top 50 oil companies in the world and the fourth largest oil company in Latin America. The Company is also involved in exploration and production activities in Brazil, Peru and the United States Gulf Coast, and owns the main refineries in Colombia, most of the network of oil and multiple purpose pipelines in the country, petrochemical plants, and is entering into the biofuels business. This release contains forward-looking statements relating to the prospects of the business, estimates for operating and financial results, and those related to growth prospects of Ecopetrol. These are merely projections and, as such, are based exclusively on the expectations of management concerning the future of the business and its continued access to capital to fund the Company's business plan. Such forward-looking statements depend, substantially, on changes in market conditions, government regulations, competitive pressures, the performance of the Colombian economy and the industry, among other factors; therefore, they are subject to change without prior notice. Website: www.ecopetrol.com.co SOURCE Ecopetrol S.A.